Light bulb



FIG. 1 is an elevational view of an embodiment of the invention;

FIG. 2 is an elevational view of the same embodiment rotated 90 degrees;

FIG. 3 is a top view of the embodiment of the invention; and,

FIG. 4 is a plan view of the embodiment of the invention.

The elements for which the design is claimed are shown in solid lines, the dashed lines showing environmental shructure. 

The ornamental design for a light bulb, substantially as shown and described. 